Running the XJ-A140 With Missing Diodes

[rhd]

i had uploaded this one but removed it cause i thought i screwed up....Attachment 28128....there are some mistakes in this one..thats fore sure.

Yes..mistakes Ignore the per-diode polarity. You have one polarity on one side of the loop, another on the other. That's all you care about. Each loop is a SERIES string of LDs.

In terms of heat, I don't think it's too big of a deal. The LEDs on my setup are arctic silvered to the heatsink. The diodes I've been testing with are out in open air. Since each one is only dissipating about a watt of heat, that has seemed to be fine for now. That said, I always figured that a permanent system with a PCB would require affixing the diode side of the PCB to the heatsink top fins, for long runtimes.

Also, if I can make a little request - I'm not on this forum very often, but I know that on most forums people tend to get frustrated if you double or triple post instead of just editing your most recent unreplied message. Can you edit your posts instead of multi-posting? I find it very scattered and frustrating to follow

[kobra000]

oh sorry about that.ill keep them short and sweet from now on.=)

ok now here is a question i havnt touched on before..the collimation...do you know what the proper setup would be (i have no idea about collimation.serious math involved)...

i do know that most of our light is lost if the collimation is incorrect ..have you tried any experiments with this to find a good setup?
i think of it light water,..if water can be forced,formed and contained then the same should apply with light....thats what i had in mind when i talked about mounting the led as close to the primary dichro as possible..so as little of the light would be lost as possible..and that led me to choosing those high power leds (6000 and 8000 lumens blue)..i figured i could compensate with "massive volume of light" for the lost light with like a brute force tactic
that one led that i posted a while back was like 2000-3000 lumens @ 1.5 amp. i figured even if it were fed 1 amp it should still theoretically be possible to get 1500,1800 maybe just maby 2000 lumens out of it.(doubtful)..and that only leaves 500ma to feed to diodes or resistors. i mean 1 amp aint child play.Ive heard 1 amp can kill under the right circumstances.
im also looking into the Blue Phlatlights...the same as the stock red led in the projo....those have a wonderful power curve..less then 1 am and as high as 9 amps..but i cant find anywhere to buy them.

you said white leds would be next to futile....how come?

[kobra000]

a friend of mine (who is a wiz with electronics and whatnot)..gave me an explanation of how a DLP works..here is what he said

""""The way the color image is formed on a single DLP projector is that each frame you display each of the color separately so there is the red image for some milliseconds then is the green and the the blue image but the brain is not that fast and it will see a combination of this images.
So it make sense that each color is 33.3% on if there are no dead portions when none of the colors is displayed then it may be 30%.
My guess is that part of the Blue lasers are pulsed separately for the green color.
Not sure you understood so I will give you a more concrete example say the projector is working at 60 frame / second and one second is 1000ms then one frame is about 1000/60 = 16ms then each color will be on about 5ms and off for 11ms so
red on 5ms, blue and green off
next green on , 5ms blue and red off
and finally blue on 5ms, green and red off
so a total of 16ms (5ms was a round number)
Then this will repeat for the next frame.
So you understand why the Blue and Green LED need to work in this way with this pulses and need to be synchronized with the projector. """"


that put alot of things into perspective for me.

[rhd]

White LEDs are a waste, because you only want such a narrow band of their output that you're effectively loosing all the light from ~460 and up, which is probably 80% of its output.

I don't know very much about collimation at all. In fact, next to nothing. The knowledge exists in this forum without doubt. However, I'm not sure whether an LED emitter of this size even can be reasonably collimated.

My sense is that the only workable solution would be to get blue and green emitters placed further into the optics - and realistically I think this would be as much of a hassle as just building your own projector from scratch The problem with a Blue Phlatlight as mentioned is that you've got high voltage low current, and the Phlatlight wants high current low voltage.

Regarding DLP pulses - I'm not sure that they're evenly timed. IE, I don't know that you actually have a straight division of 3 for each colour. I would imagine that they scale the pulse time based on the power of each light source. That may not actually be the case, but it seems logical that it could. I'm *guessing* that the green pulsing is achieved by virtual of the break in the spining phosphor disc. That's pure speculation though - I haven't given much thought to or done much testing on that aspect of the projector yet.

Something was suggested over at LPF that has diverted my attention away from trying to get BLUE/GREEN running. That was.... getting this projector to output B&W. This is likely a much simpler task:
- Swap the RED phlatlight with a similar spec'd white emitter (there are a few)
- Smooth the pulsing of the phlatlight so that it stays on for the full RGB cycle

I think a B&W retro projector would be pretty cool in it's own right.

[kobra000]

yeah seems easier to get it to be black and white than anything else.... hey what if we popped a color wheel in front of the light we swapped for the phatlight? all we gotta do is get some form and amount of light to that dlp chip and we got a viable projector...might not as good as it once was but it will be close.or close ish. Im starting to think i might get 3 or 4 lasers and pop back in and see what kind screen i get,just dont know what to do with the remaining laser positions..dupe them with diodes or resistors? or just short crossed the pad. they are roughly priced the same as the leds i have been looking at (LEDs $40-$75 each,lasers $35- $40 each) but im still not wanting to write that monster 100watt 8000 lumen led off
if only 50 percent is getting in and only 20-25% percent of that is making it out the projection lens then that should be about or close to 800-1000 lumens....not bad.but certainly not great. i have found some 300 watt 27,000 lumen....but those things are so hot you can practically weld with them.

I know phatlight has some RGB leds out there...not sure of the currrent or voltage draw...here is a great .pdf file on them..http://www.nefc.com/NEFC_Downloads/N...Light_9_06.pdf....shows a graphic illustration which states that no color wheel or filtration is needed when sending the light to the DLP (look at page 10)

also this pic shows the basic principal i guess its using dichros for color mixing.
and here is a link to the downloads for all color phlatlights http://www.luminus.com/products/color.html
like you said if we can get the phatlight to pulse right...we might have it with a RGB Phlatlight in place of the RED phlatlight..then all we have to do is dupe the ENTIRE flexpcb cable with diodes or resistors or a big resistor to get it to turn on the led.
hmm..that just might be it. and im sure the Phalight is easier to collimate than other Leds.. here is a thread over at LPF showing a dude messing around with a red one(out of the xja projo i assume )
but im more interested in the way he collimated it then anything else. does the red phatlight on the projector have its own collimator lens? cause thats what i constantly see when i see pics of it...this large dome lens in front of it.
http://laserpointerforums.com/f66/ph...tml#post739295
Here is the data sheet on the SMB-160 it says 550 lumens @4amps..but i heard these things can be driven as high as 9 amps.. (wonder if the projector is capable of that..if not i know a external power supply is,just dont know how we would pulse it if it was externally powered)http://www.luminus.com/products/data..._Datasheet.pdf

I see the pros of usin an RGB phatlight like this
its got its own TEC cooler and heat sink
the projector is already expecting a phatlight to be there..so as long as the voltage and current are the same,shouldn't be any different
pulsing a single led might be alot easier than trying to get 2 leds (blue and red)to pulse together,not to mention whatever the phosphor wheel needs.
using the stock red led location,we have more of a straight path to the DLP..a few dichros on the way but that might be a good thing.
dont have to worry about the voltage and whatnot of the Flexcable.cause it wont be used.except for a dummy load to get the projector to turn on.
i really dont think we need the phosphor wheel any more with this setup.

The only con i can see is this
getting as much power out of the RGB phatlight that we can with whatever voltage/current is usually sent to the red led.(if insufficient voltage is encountered,perhaps a transformer/buck boost of some type could be used)
collimation of its light (but i think this is already done with the stock red led lens correct?)
pulsing it at the correct frequency to match the DLP chip.and get a smooth color gamut. do we pulse external or try to let the main board do it?.(i dont think it can be done with the main board.)

i know im going to try the RBG phatlight.wish me luck


Keith.

ps

just found this....this is neat!http://www.dealextreme.com/p/144w-rg...t-dc-12v-73695
Also..i think something like this would be perfect for dialing in our color intensisty if a RGB led is used...of any type id assume...http://www.dealextreme.com/p/28-key-...dc12-24v-73676 led controller with 28 digit remote control controls dim control and individual LED color control.
something similar..but i belive it allows for faster or slower pulsing..not sure..remote says speed up/speed down. http://www.dealextreme.com/p/144w-rg...p-dc-12v-94206

[kobra000]

well i contacted the maker of phlatlights and this is what they said in their first email:

"Thank you for contacting Luminus. We do offer 2, standard RGBW products, each having individually addressable LEDs: The SBM-160 is a surface-mount package capable of generating up to 1500 lumens at full power. The CBM-380 is a coreboard package capable of generating up to 3900 lumens at full power.
Product datasheets with much more detailed information for both of these LEDs can be found at our website (www.luminus.com) under the "Products / Color Mix LEDs" section.
Best regards,
Andrei

Second email is as follows.

Hello Keith,
Yes - each LED can be independently controlled. With all 4 LEDs (R, G, B and W) on at full current you will achieve maximum total luminous flux (lumens). Since each LED can be controlled, you can achieve a pure R, G, B image and practically any combination in between by driving each LED differently.
Luminus LEDs can be purchased through our distributors, Avnet (www.avnet.com) and Mouser (www.mouser.com). Please check the distributor websites for stock/availability of these parts (the SBM-160 is quite new; not sure if the distributors have this product yet).
Best regards,

Andrei


Im pretty confident the CBM-380 will do well in place of the Red LED..now we just got figure out how to pulse it in time with the DLP... (think that might be that difficult?)
Now if i can just get over the 163 dollar mouser price tag..thats the price of 4 lasers....yeah the idea of putting the lasers back in is starting to look real good.

Keith.

[rhd]

Take a look at the lumen output for the blue channel on the CBM-380. I think that would be way too low.

I like this line of thinking, but I see a couple potential issues:

- How would we time the cycling between BLUE and GREEN on the RGB emitter that we replace the phlatlight with?
- How are we going to take the ~28V and ~500mA-1A from an LD channel, and turn it into the low-volt high-current a CBM-380 (or similar) requires? We'd need a buck driver capable of ~8A, and that's not an easy task.

[kobra000]

yeah i have been turned off of that idea by the CBM-380S price of 163 bucks.plus it cant put out blue for squat!...sigh i think im just going to get some LD's and pop them back in...when stacked up against the LEDs i want they are the cheapest choice (40 bucks a pop) a few others i have been in contact with have said that the projector will run very well and produce a great screen with as few as 4 LD'S.
Modding other projectors is a walk in the park next to this one.

Did you take a look at the gadgets and things i had posted at the bottom of #176?...perhaps some of those will work.

though the idea you had mentioned of placing a white led there instead of the red and making B/W projector still toys with my mind...i just wonder if we placed a color wheel in front of it if it would do the job.

Now im starting to see why they used the lasers in the first place..they knew that there was hardly a LED on the market capable of making 2300 lumens of blue light (except for the planar leds which are too big).the red led i understand and the phosphor screen i understand as well.gotta have someway of making green light when you have limited space....but dang why did they have to go and make it so complicated. Other DLP projectors you trick a optocoupler or photo resistor or two or ground a control wire and stick a led in there and boom you got a projector that lasts 50,000 hours...But the Kaso noooo! they want you to have a aneurism trying to mod this one!
sorry not having a good day and these things are really upsetting me.

[kobra000]

here is a great video showing how the internals work.




0:36 where it shows that red led.why dont we just put a white led there and a color wheel perhaps the color wheel could run off the phosphor screen connector? or if the motor doesn't take too much,just wire it into the power source of the Red led ( i know its a shot in the dark on that one just an idea)
or perhaps just bank a blue and green laser onto the red led (separate independent power source) and have it shoot in the same path as the red and bypass the phosphor screen ya know take a more direct approach/route to the DLP


this picture gave me some inspiration and ideas






keith

[rhd]

I've said this twice now, you can't just place a filter in front of any old light source and magically turn all that light into the color of the filter. That's not how...light works. If you shine a red light source through a filter that passes only blue, you get..... Nothing. Regarding the color wheel, neat idea, but as I questioned before, how would you keep it synchronized?

I thought LPF was frustrating! This triple posting is getting to be too chaotic, and we're going in circles with ideas that have already been addressed. I need to take a recess from this thread for my own sanity.